Arch Linux

elahav

Member

From: Ottawa, ON

Registered: 2005-04-18

Posts: 90

USB serial console

I need to run a serial console on my laptop in order to get information on a kernel panic. Since the laptop does not have a serial connector, I would like to use a serial console over USB. I have enabled the required options in the kernel (CONFIG_USB_SERIAL=y and CONFIG_USB_SERIAL_CONSOLE=y), but I have a problem due to Arch's device naming. I believe that the kernel expects a device name of the form ttyUSB0, which should be located under /dev. However, with Arch (because of udev?) this device is called USB0 and is located under /dev/tts.
How can I pass this information to the kernel? I tried console=tts/USB0, but then it just hangs during boot.

Elad

tomk

Forum Fellow

From: Ireland

Registered: 2004-07-21

Posts: 9,839

Re: USB serial console

After your system has booted, the device name you see under /dev is indeed due to udev - here's the relevant rule:

KERNEL=="ttyUSB[0-9]*", NAME="tts/USB%n"

However, at boot time, udev hasn't run yet, so the kernel name ttyUSBx should work.